High-strength rubber composition comprising an aromatic polyphenol derivative

ABSTRACT

A rubber composition comprises at least one phenol-aldehyde resin based: on at least one derivative of an aromatic polyphenol comprising at least one aromatic ring bearing at least two —O—Z groups in the meta position relative to one another, the two positions ortho to at least one of the —O—Z groups being unsubstituted, Z being other than hydrogen, and on at least one aldehyde.

FIELD OF THE INVENTION

The invention relates to rubber compositions, a method for manufacturingthese compositions, a rubber composite and a tyre.

RELATED ART

It is known to use, in some parts of the tyres, rubber compositionshaving high stiffness during small strains of the tyre. Resistance tosmall strains is one of the properties which a tyre must have in orderto respond to the stresses to which it is subjected.

High stiffness may be obtained using what is referred to as aconcentrated vulcanization system, that is to say especially comprisingrelatively high contents of sulfur and of vulcanization accelerator.

Nonetheless, such a concentrated vulcanization system detrimentallyaffects the uncured ageing of the composition. Thus, when thecomposition is in the form of a semi-finished product, for example of arubber strip, the sulfur may migrate to the surface of the semi-finishedproduct. This phenomenon, referred to as blooming, leads to adetrimental effect on the green tack of the semi-finished product duringprolonged storage thereof, with, as consequence, degradation of theadhesion between the semi-finished products during manufacture of thetyre.

Moreover, storage of the uncured composition containing a concentratedvulcanization system is liable to lead to a reduction in the delay phaseof the composition during vulcanization thereof, that is to say the timepreceding the start of vulcanization. Consequently, the composition maybegin to cure prematurely in certain forming tools and the vulcanizationkinetics are liable to be altered and the vulcanization efficiency to bereduced.

Such a concentrated vulcanization system also detrimentally affectsageing in the cured state. Indeed, degradation of the mechanicalproperties of the cured composition is observed, especially at thelimits, for example of the elongation at break.

High stiffness may otherwise be obtained by increasing the content ofreinforcing filler.

Nonetheless, in a known way, increasing the stiffness of a rubbercomposition by increasing the content of filler may detrimentally affectthe hysteresis properties and thus the rolling resistance properties oftyres. However, it is an ongoing aim to lower the rolling resistance oftyres in order to reduce the consumption of fuel and thus to protect theenvironment.

Finally, high stiffness may be obtained by incorporating certainreinforcing resins, as disclosed in WO 02/10269.

Conventionally, the increase in stiffness is obtained by incorporatingreinforcing resins based on a methylene acceptor/donor system. The terms“methylene acceptor” and “methylene donor” are well known to thoseskilled in the art and are widely used to denote compounds capable ofreacting together to generate, by condensation, a three-dimensionalreinforcing resin which will become superimposed and interpenetratedwith the reinforcing filler/elastomer network, on the one hand, and withthe elastomer/sulfur network, on the other hand (if the crosslinkingagent is sulfur). The methylene acceptor is combined with a hardener,capable of crosslinking or curing it, also commonly known as a methylenedonor. Examples of such methylene acceptors and donors are described inWO 02/10269.

The methylene donors conventionally used in rubber compositions fortyres are hexamethylenetetramine (abbreviated to HMT) orhexamethoxymethylmelamine (abbreviated to HMMM or H3M) orhexaethoxymethylmelamine.

The methylene acceptors conventionally used in rubber compositions fortyres are pre-condensed phenolic resins.

Nonetheless, the combination of phenolic resin, conventionally used asmethylene acceptor, with HMT or H3M as methylene donor producesformaldehyde during the vulcanization of the rubber composition.However, it is desirable to reduce, or even eliminate in the long run,formaldehyde from rubber compositions due to the environmental impact ofthese compounds and the recent developments in regulations, especiallyEuropean regulations, relating to this type of compound.

SUMMARY OF THE INVENTION

The objective of the invention is to provide a rubber composition whichis stiffened by means of low-environmental-impact compounds.

To this end, a subject of the invention is a rubber compositioncomprising at least one phenol-aldehyde resin based:

-   -   on at least one derivative of an aromatic polyphenol comprising        at least one aromatic ring bearing at least two —O—Z groups in        the meta position relative to one another, the two positions        ortho to at least one of the —O—Z groups being unsubstituted, Z        being other than hydrogen, and    -   on at least one aldehyde.

The combination of the aldehyde and of the aromatic polyphenol obtainedfrom an aromatic polyphenol derivative of the composition according tothe invention makes it possible to obtain rubber compositions having anequivalent or even vastly improved stiffness at low strain compared toconventional rubber compositions which comprise methylene donors HMT orH3M and compared to the rubber compositions devoid of reinforcing resin.

In accordance with the invention, the reinforcing phenol-aldehyde resinis based on the aromatic polyphenol derivative and on an aldehyde and ismanufactured in situ, by crosslinking, in the rubber composition,especially during the crosslinking of this rubber composition, forexample by vulcanizing or curing.

Furthermore, the derivatives of the aromatic polyphenols of thecomposition according to the invention make it possible to avoid apremature crosslinking of the phenol-aldehyde resin. Specifically, oneproblem linked to the use of certain reinforcing resins, especiallythose based on the corresponding aromatic polyphenol and on thecorresponding aldehyde, is their ability to crosslink prematurely.Indeed, after the step of manufacturing the composition comprising theconstituents of these reinforcing resins, the composition is shaped forexample by calendering, for example in the form of a sheet or a slab, orelse is extruded, for example to form a rubber profiled element. Yet,due to their ability to crosslink rapidly, these reinforcing resinsbased on the corresponding aromatic polyphenol and on the correspondingaldehyde crosslink and stiffen the composition, which may hamper theshaping of the rubber composition. In fact, the aromatic polyphenolderivative and the aldehyde react less quickly than the correspondingaromatic polyphenol and the corresponding aldehyde. This rate ofreaction may be determined by measuring the change in the rheometrictorque as a function of the time. This change describes the stiffeningof the composition following in particular the crosslinking of thephenol-aldehyde resin. From the comparison of the change in therheometric torques of a first composition comprising the derivative ofthe aromatic polyphenol and the aldehyde and of a second compositioncomprising the corresponding aromatic polyphenol and the correspondingaldehyde, it is seen that the derivative of the aromatic polyphenolmakes it possible to delay the crosslinking of the phenol-aldehyde resinrelative to the direct reaction between the aromatic polyphenol and thealdehyde.

The inventors behind the invention put forward the hypothesis that thederivative of the aromatic polyphenol is a precursor of the aromaticpolyphenol and that the latter makes it possible to avoid a prematurecrosslinking of the phenol-aldehyde resin due to the Z radical of each—O—Z group which is other than hydrogen. Specifically, the Z radical ofeach —O—Z group would act as a temporary protective group enabling,according to the hypothesis of the inventors, the formation of ahydroxyl function under predetermined reaction conditions and thereforethe formation of the corresponding aromatic polyphenol. Thepredetermined reaction conditions under which this formation is possibledepend on several parameters such as the pressure, the temperature orelse the chemical species present in the reaction medium. These reactionconditions depend on the —O—Z group and are easily determinable, or evenknown by a person skilled in the art. For example, such reactionconditions are the heating of the rubber composition to a temperaturegreater than or equal to 80° C., preferably to 100° C. and morepreferentially to 120° C.

The —O—Z group is such that the reaction between the derivative of thearomatic polyphenol and the aldehyde enables the crosslinking of thephenol-aldehyde resin. Preferably, the —O—Z group is such that thereaction between the derivative of the aromatic polyphenol and thealdehyde enables the crosslinking of the phenol-aldehyde resin under thesame reaction conditions, preferably the same temperature reactionconditions, as a phenol-aldehyde resin based on the correspondingaromatic polyphenol (comprising hydroxyl groups instead of —O—Z groups)and on the same aldehyde. Conventionally, the temperature is greaterthan or equal to 120° C., preferably greater than or equal to 140° C.

Furthermore, the specific combination of the aldehyde and of thearomatic polyphenol derivative according to the invention makes itpossible to obtain rubber compositions that have excellent stiffnessretention with the increase in temperature, this retention beingequivalent, or even greater in most embodiments, than that of rubbercompositions devoid of reinforcing resin. The specific combination ofthe aldehyde and of the aromatic polyphenol derivative according to theinvention also makes it possible to obtain rubber compositions that haveexcellent stiffness retention with the increase in temperature, thisretention being equivalent, or even greater in certain embodiments, thanthat of conventional rubber compositions that comprise HMT or H3Mmethylene donors. As already explained above, the inventors behind theinvention put forward the hypothesis that the aromatic polyphenolderivative (comprising hydroxyl groups instead of —O—Z groups) is aprecursor of the corresponding aromatic polyphenol. As already explainedabove, this makes it possible to avoid an immediate crosslinking of thephenol-aldehyde resin owing to a reaction that would generate, after adelay, the hydroxyl function functions from the aromatic polyphenolderivative (comprising hydroxyl groups instead of —O—Z groups).Specifically, the —O—Z groups would act as temporary protective groupsenabling, according to the hypothesis of the inventors, the formation ofhydroxyl functions under predetermined reaction conditions (in otherwords the regeneration of the aromatic polyphenol corresponding to thederivative). The time taken to regenerate the aromatic polyphenol, evenwhen it is very short, for example of the order of a minute, wouldenable a better dispersion of the aldehyde and of the aromaticpolyphenol derivative (comprising hydroxyl groups instead of —O—Zgroups) in the reaction mixture which would make it possible to obtain aphenol-aldehyde resin having a more homogeneous crosslinking andtherefore a better temperature resistance of the phenol-aldehyde resin.

The name “aromatic polyphenol derivative” is used due to the structuralsimilarity existing between the aromatic polyphenol derivative and thecorresponding aromatic polyphenol. Specifically, the aromatic polyphenolderivative has a structure analogous to that of the correspondingaromatic polyphenol but in which the hydrogen of at least two hydroxylfunctions is replaced by the Z radical. Thus, the aromatic polyphenolderivative has a general formula (W) below:

in which Ar is the aromatic ring. An aromatic polyphenol derivativeshould not be understood as meaning that it can be a pre-condensed resinwhich would comprise hydroxyl functions enabling the reaction with thealdehyde.

The expression “resin based on” should, of course, be understood asmeaning a resin comprising the mixture and/or the reaction product ofthe various base constituents used for this resin, it being possible forsome of them to be intended to react or capable of reacting with oneanother or with their immediate chemical surroundings, at least partly,during the various phases of the method for manufacturing thecomposition, the composites or the tyre, in particular during a curingstage. Thus, provision could also be made for the aldehyde to be derivedfrom a precursor of this aldehyde. For example, should formaldehyde beused as aldehyde, a precursor of the formaldehyde would behexamethylenetetramine (HMT).

“Meta position relative to one another” is intended to mean that the—O—Z groups are borne by carbons of the aromatic ring which areseparated from one another by a single other carbon of the aromaticring.

“Position ortho to a group” is intended to mean the position occupied bythe carbon of the aromatic ring which is immediately adjacent to thecarbon of the aromatic ring bearing the group.

Within the context of the invention, the carbon-based products mentionedin the description may be of fossil or biobased origin. In the lattercase, they may partially or completely result from biomass or beobtained from renewable starting materials resulting from biomass.

The rubber composition thus comprises at least one (that is to say, oneor more) phenol-aldehyde resin; this phenol-aldehyde resin being basedon at least one (that is to say, one or more) aldehyde and at least one(that is to say, one or more) derivative of an aromatic polyphenol,which constituents will be described in detail below.

Preferably, the derivative of the aromatic polyphenol is obtained by amanufacturing method in which the following are reacted:

-   -   an aromatic polyphenol comprising at least one aromatic ring        bearing at least two —OH hydroxyl functions in the meta position        relative to one another, the two positions ortho to at least one        of the —OH hydroxyl functions being unsubstituted, and    -   a compound that makes it possible to form the —O—Z group from        each hydroxyl function.

In certain preferential embodiments, all the —O—Z groups are identical.However, in other embodiments, at least two —O—Z groups are different.

Preferably, the molar mass of each —O—Z group is less than or equal to1000 g·mol⁻¹. Typically, the molar mass of each —O—Z group is between 15g·mol⁻¹ and 1000 g·mol⁻¹, preferentially between 15 g·mol⁻¹ and 500g·mol⁻¹.

In the present description, unless expressly indicated otherwise, allthe percentages (%) shown are percentages by weight. The acronym “phr”signifies parts by weight per hundred parts of elastomer.

Furthermore, any range of values denoted by the expression “between aand b” represents the range of values extending from more than a to lessthan b (in other words excluding the limits a and b), whereas any rangeof values denoted by the expression “from a to b” means the range ofvalues extending from the limit “a” as far as the limit “b”, in otherwords including the strict limits “a” and “b”.

Another subject of the invention is a rubber composition comprising:

-   -   at least one derivative of an aromatic polyphenol comprising at        least one aromatic ring bearing at least two —O—Z groups in the        meta position relative to one another, the two positions ortho        to at least one of the —O—Z groups being unsubstituted, Z being        other than hydrogen, and    -   at least one aldehyde.

Another subject of the invention is a method for manufacturing a rubbercomposition comprising a step of mixing:

-   -   at least one derivative of an aromatic polyphenol comprising at        least one aromatic ring bearing at least two —O—Z groups in the        meta position relative to one another, the two positions ortho        to at least one of the —O—Z groups being unsubstituted, Z being        other than hydrogen, and    -   at least one aldehyde.

Preferably, during the mixing step, at least one elastomer is also mixedinto the composition.

Another subject of the invention is a method for manufacturing a rubbercomposition in the cured state, comprising:

-   -   a step of manufacturing a rubber composition in the uncured        state comprising a step of mixing:        -   at least one derivative of an aromatic polyphenol comprising            at least one aromatic ring bearing at least two —O—Z groups            in the meta position relative to one another, the two            positions ortho to at least one of the —O—Z groups being            unsubstituted, Z being other than hydrogen, and        -   at least one aldehyde,    -   then, a step of shaping the rubber composition in the uncured        state,    -   then, a step of vulcanizing the rubber composition during which        a phenol-aldehyde resin based on the aromatic polyphenol        derivative and on the aldehyde is crosslinked.

Alternatively, the step of crosslinking by vulcanizing or curing may bereplaced by a step of crosslinking using a crosslinking system otherthan sulfur.

As explained above, the inventors put forward the hypothesis accordingto which, during the crosslinking step, for example by vulcanizing orcuring, the following are carried out, prior to the crosslinking of theresin:

-   -   a step of forming the aromatic polyphenol from the derivative or        precursor of the aromatic polyphenol by formation, on the        aromatic ring, of at least two hydroxyl functions in the meta        position relative to one another, the two positions ortho to at        least one of the hydroxyl functions being unsubstituted, each        hydroxyl function being obtained from each —O—Z group, and    -   a step of crosslinking a phenol-aldehyde resin starting from the        aromatic polyphenol and the aldehyde.

Yet another subject of the invention is a rubber composition capable ofbeing obtained by a method as described above.

Another subject of the invention is a rubber composite reinforced withat least one reinforcing element embedded in a rubber composition asdescribed above.

Another subject of the invention is a tyre comprising a rubbercomposition as described above or a rubber composite as described above.

Rubber composition is intended to mean that the composition comprises atleast one elastomer or a rubber (the two terms being synonyms) and atleast one other component. A rubber composition thus comprises a matrixof elastomer or of rubber in which at least the other component isdispersed. A rubber composition is in a plastic state in the uncured(non-crosslinked) state and in an elastic state in the cured(crosslinked) state, but never in a liquid state. A rubber compositionmust not be confused with an elastomer latex, which is a composition ina liquid state comprising a liquid solvent, generally water, and atleast one elastomer or a rubber dispersed in the liquid solvent so as toform an emulsion. Thus, the rubber composition is not an aqueousadhesive composition.

Yet another subject of the invention is the use of an aromaticpolyphenol derivative comprising at least one aromatic ring bearing atleast two —O—Z groups in the meta position relative to one another, thetwo positions ortho to at least one of the —O—Z groups beingunsubstituted, Z being other than hydrogen, for the manufacture of aphenol-aldehyde resin for reinforcing a rubber composition.

The aromatic polyphenol derivative may also be preferentially used forgenerating a delay phase during the crosslinking of a phenol-aldehyderesin based on the aromatic polyphenol derivative and on an aldehyde.

In certain embodiments, the aromatic polyphenol derivative may be usedin a phenol-aldehyde resin to maintain the stiffness of a rubbercomposition with the increase in the temperature.

Preferably, the rubber composition is as described below.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic drawing of a radial section of a tire inaccordance with the invention.

FIG. 2A is the 1H NMR spectrum of derivative (5); and FIG. 2B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 3A is the 1H NMR spectrum of derivative (6); and FIG. 3B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 4A is the 1H NMR spectrum of derivative (7); and FIG. 4B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 5A is the 1H NMR spectrum of derivative (8); and FIG. 5B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 6A is the 1H NMR spectrum of derivative (9); and FIG. 6B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 7A is the 1H NMR spectrum of derivative (10); and FIG. 7B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

FIG. 8A is the 1H NMR spectrum of derivative (11); and FIG. 8B is arepresentation of the change in the rheometric torque of relatedcompositions of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Derivative of the Aromatic Polyphenol of the Rubber Composition

An essential constituent of the resin and of the composition is anaromatic polyphenol derivative comprising one or more aromatic ring(s).The aromatic polyphenol derivative comprises at least one aromatic ringbearing at least two —O—Z groups in the meta position relative to oneanother, the two positions ortho to at least one of these —O—Z groupsbeing to unsubstituted.

In accordance with the invention, the aromatic polyphenol derivative maybe, in one embodiment, a simple aromatic polyphenol derivative moleculecomprising one or more aromatic rings, at least one of these aromaticrings, or even each aromatic ring, bearing at least two —O—Z groups inthe meta position relative to one another, the two positions ortho to atleast one of these —O—Z groups being unsubstituted.

Such simple molecules do not comprise a repeat unit.

In accordance with the invention, the aromatic polyphenol derivative maybe, in another embodiment, a pre-condensed resin based:

-   -   on at least one aromatic polyphenol comprising at least one        aromatic ring bearing at least two hydroxyl functions in the        meta position relative to one another, the two positions ortho        to at least one of the hydroxyl functions being unsubstituted;        and    -   on at least one compound comprising at least one aldehyde        function, the hydroxyl functions of the pre-condensed resin that        are free at the end of the condensation of the pre-condensed        resin being substituted by —O—Z groups.

Such a pre-condensed resin based on aromatic polyphenol is in accordancewith the invention and comprises, unlike the simple molecule describedabove, a repeat unit. In this case, the repeat unit comprises at leastone aromatic ring bearing at least two —O—Z groups in the meta positionrelative to one another, the two positions ortho to at least one ofthese —O—Z groups being unsubstituted. In this embodiment, in order toform the aromatic polyphenol derivative in pre-condensed resin form, thepre-condensed resin based on an aromatic polyphenol comprising at leastone aromatic ring bearing at least two —OH hydroxyl functions in themeta position relative to one another, the two positions ortho to atleast one of the —OH hydroxyl functions being unsubstituted, is formedand this pre-condensed resin is reacted with a compound that makes itpossible to form the —O—Z group from each hydroxyl function left free atthe end of the condensation of the pre-condensed resin.

In another embodiment, the aromatic polyphenol derivative is a mixtureof a derivative of an aromatic polyphenol forming a simple molecule andof a pre-condensed resin based on aromatic polyphenol in which thehydroxyl functions of the pre-condensed resin that are free at the endof the condensation of the pre-condensed resin are substituted by —O—Zgroups.

In the particular embodiments that follow, the aromatic ring or rings ofthe aromatic polyphenol derivative are described. For the sake ofclarity, the “derivative of the aromatic polyphenol” is describedtherein in its simple molecule form. The aromatic polyphenol at theorigin of the corresponding derivatives could then be condensed and willin part define the repeat unit. The characteristics of the pre-condensedresin are described in greater detail below.

In a preferred embodiment, the aromatic ring of the derivative of thearomatic polyphenol bears three —O—Z groups in the meta positionrelative to one another.

The two positions ortho to each —O—Z group are preferably unsubstituted.This is intended to mean that the two carbon atoms located on eitherside of (in the position ortho to) the carbon atom bearing the —O—Zgroup just bear a hydrogen atom.

Even more preferentially, the remainder of the aromatic ring of thederivative of the aromatic polyphenol is unsubstituted. This is intendedto mean that the other carbon atoms of the remainder of the aromaticring (those other than the carbon atoms bearing —O—Z groups) just bear ahydrogen atom.

In one embodiment, the derivative of the aromatic polyphenol comprisesseveral aromatic rings, at least two of these each bearing at least two—O—Z groups in the meta position relative to one another, the twopositions ortho to at least one of the —O—Z groups of at least onearomatic ring being unsubstituted.

In a preferred embodiment, at least one of the aromatic rings of thederivative of the aromatic polyphenol bears three —O—Z groups in themeta position relative to one another.

The two positions ortho to each —O—Z group of at least one aromatic ringare preferably unsubstituted.

Even more preferentially, the two positions ortho to each —O—Z group ofeach aromatic ring are unsubstituted.

Advantageously, the, or each, aromatic ring of the derivative of thearomatic polyphenol is a benzene ring.

Mention may in particular be made, as example of aromatic polyphenolderivative comprising just one aromatic ring, of the derivatives ofresorcinol and of phloroglucinol, of structural formulae:

By way of example, in the case in which the derivative of the aromaticpolyphenol comprises several aromatic rings, at least two of thesearomatic rings, which are identical or different, are selected fromthose of general formulae:

in which the Z₁ and Z₂ symbols, which are identical or different, ifthere are several of them on the same aromatic ring, represent an atom(for example, carbon, sulfur or oxygen) or a connecting group, bydefinition at least divalent, which connects at least these two aromaticrings to the remainder of the derivative of the aromatic polyphenol.

Another example of aromatic polyphenol derivative is a derivative of2,2′,4,4′-tetrahydroxydiphenyl sulfide, a derivative that has thefollowing structural formula:

Another example of aromatic polyphenol derivative is a derivative of2,2′,4,4′-tetrahydroxydiphenyl benzophenone, a derivative of thefollowing structural formula:

It is noted that each compound IV and V is an aromatic polyphenolderivative comprising two aromatic rings (of formulae III-c), each ofwhich bears at least two (in this instance two) —O—Z groups in the metaposition relative to one another.

It is noted, in the case of a derivative of an aromatic polyphenolcomprising at least one aromatic ring in accordance with formula III-b,that the two positions ortho to each —O—Z group of at least one aromaticring are unsubstituted. In the case of a derivative of an aromaticpolyphenol comprising several aromatic rings in accordance with formulaIII-b, the two positions ortho to each —O—Z group of each aromatic ringare unsubstituted.

According to one embodiment of the invention, the aromatic polyphenolderivative is selected from the group consisting of a derivative ofresorcinol (I), a derivative of phloroglucinol (II), a derivative of2,2′,4,4′-tetrahydroxydiphenyl sulfide (IV), a derivative of2,2′,4,4′-tetrahydroxybenzophenone (V) and the mixtures of thesecompounds. In a particularly advantageous embodiment, the derivative ofthe aromatic polyphenol is a derivative of phloroglucinol (II).

In one embodiment, the aromatic polyphenol derivative comprises apre-condensed resin based on at least one aromatic polyphenol asdescribed in any one of the embodiments described in the presentapplication, the hydroxyl functions of the pre-condensed resin that arefree at the end of the condensation of the pre-condensed resin beingsubstituted by —O—Z groups.

This pre-condensed resin is advantageously based:

-   -   on at least one aromatic polyphenol as defined above, and        preferentially selected from the group consisting of resorcinol,        phloroglucinol, 2,2′,4,4′-tetrahydroxydiphenyl sulfide,        2,2′,4,4′-tetrahydroxybenzophenone and the mixtures thereof; and    -   on at least one compound comprising at least one aldehyde        function.

The compound that comprises at least one aldehyde function and thatreacts with said aromatic polyphenol may be an aldehyde as definedbelow. Advantageously, said compound comprising at least one aldehydefunction is selected from the group consisting of formaldehyde,benzaldehyde, furfuraldehyde, 2,5-furandicarboxaldehyde,1,4-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldehyde,1,2-benzenedicarboxaldehyde and the mixtures of these compounds.

Thus, in the pre-condensed resin based on aromatic polyphenol, therepeat unit comprises at least one aromatic ring bearing at least twohydroxyl functions in the meta position relative to one another, atleast one of the carbon atoms of the aromatic ring, which wasunsubstituted before the condensation of the pre-condensed resin, beingconnected to another unit.

Irrespective of the compound other than the aromatic polyphenol at theheart of the pre-condensed resin, this pre-condensed resin is devoid offree formaldehyde. Specifically, even in the case where thepre-condensed resin is based on an aromatic polyphenol as describedpreviously and on formaldehyde, since the formaldehyde has alreadyreacted with the aromatic polyphenol, the pre-condensed resin is devoidof free formaldehyde liable to be able to react with an aldehyde inaccordance with the invention in a subsequent step.

The aromatic polyphenol derivative may also comprise a mixture of a freearomatic polyphenol derivative molecule and of a pre-condensed resinbased on aromatic polyphenol, the hydroxyl functions of thepre-condensed resin that are free at the end of the condensation of thepre-condensed resin being substituted by —O—Z groups. In particular, thearomatic polyphenol derivative may also comprise a mixture of aderivative of phloroglucinol and of a pre-condensed resin based onphloroglucinol, the hydroxyl functions of the pre-condensed resin thatare free at the end of the condensation of the pre-condensed resin beingsubstituted by —O—Z groups.

The definitions of the —O—Z group which follow apply equally to thearomatic polyphenol derivative in its simple molecule or pre-condensedresin form.

Advantageously, each —O—Z group is selected from the group consisting ofthe —O—Si(R₁R₂R₃), —O—C((═O)(R₄)) and —O—C((═O)(N(R₅R₆))) groups. EachR₁, R₂, R₃ and R₄ group represents, independently of one another, ahydrocarbon-based radical or a substituted hydrocarbon-based radical.Each R₅ and R₆ group represents, independently of one another, hydrogen,a hydrocarbon-based radical or a substituted hydrocarbon-based radical.

As temporary protective group, each —O—Z group is preferentially devoidof a function that is reactive with respect to the aldehyde. In thevarious embodiments described, each R₁, R₂, R₃, R₄, R₅ and R₆ radical ispreferentially devoid of a function that is reactive with respect to thealdehyde.

As temporary protective group, each —O—Z group is preferentially devoidof a function that is reactive with respect to the other constituents ofthe rubber composition. In the various embodiments described, each R₁,R₂, R₃, R₄, R₅ and R₆ radical is preferentially devoid of a functionthat is reactive with respect to the other constituents of the rubbercomposition.

A reactive function is understood here to mean a function that wouldreact under reaction conditions necessary for the regeneration of thearomatic polyphenol and under reaction conditions necessary for thecrosslinking of the phenol-aldehyde resin.

In one embodiment, each —O—Z group represents an —O—Si(R₁R₂R₃) groupwith R₁, R₂, R₃ representing, independently of one another, a radicalselected from the group consisting of alkyl, aryl, arylalkyl, alkylaryl,cycloalkyl and alkenyl radicals.

Preferentially, each R₁, R₂, R₃ group represents, independently of oneanother, a radical selected from the group consisting of methyl, ethyl,propyl, phenyl, allyl and vinyl radicals and more preferentially still aradical selected from the group consisting of methyl, ethyl, propyl,butyl, allyl and vinyl radicals.

In another embodiment, each —O—Z group represents an —O—C((═O)(R₄))group with R₄ representing a radical selected from the group consistingof alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl and alkenyl radicals.

In one embodiment, R₄ represents a radical comprising a single carbonatom. Preferably, R₄ represents a methyl radical. As a variant, R₄represents an O-methyl radical.

In one preferential embodiment, R₄ represents a radical selected fromthe group consisting of alkyl, allyl and vinyl radicals.

In one variant, R₄ represents an alkyl radical. In another variant, R₄represents a radical selected from the group consisting of allyl andvinyl radicals. In yet another variant, R₄ represents a radical selectedfrom the group consisting of methyl, ethyl, propyl, butyl, allyl andvinyl radicals and more preferentially R₄ represents a radical selectedfrom the group consisting of ethyl, propyl and butyl radicals.

In one embodiment, R₄ comprises at least two carbon atoms.

In one embodiment, R₄ comprises at most four carbon atoms.

In another embodiment, R₄ comprises at least five carbon atoms,preferably at least 10 carbon atoms and more preferentially at least 15carbon atoms.

In yet another embodiment, R₄ comprises at most 30 carbon atoms,preferably at most 25 carbon atoms and more preferentially at most 20carbon atoms.

In yet another embodiment, each —O—Z group represents an—O—C((═O)(N(R₅R₆))) group with R₅, R₆ representing, independently of oneanother, a radical selected from the group consisting of alkyl, aryl,arylalkyl, alkylaryl, cycloalkyl or alkenyl radicals and hydrogen.

Preferentially, each R₅, R₆ group represents, independently of oneanother, a radical selected from the group consisting of methyl, ethyl,propyl, butyl, allyl or vinyl radicals and hydrogen.

In the preceding embodiments, the propyl radicals comprise the radicalsof formula —C₃H₇. These radicals are n-propyl and isopropyl.

In the preceding embodiments, the butyl radicals comprise the radicalsof formula —C₄H₉. These radicals are n-butyl, isobutyl, sec-butyl andtert-butyl.

In the preceding embodiments, the aryl radicals comprise the aromaticrings from which a hydrogen atom has been removed. For example, the arylradical is the C₆H₅ radical obtained from benzene C₆H₆. Another exampleof an aryl radical is the C₄H₃O radical obtained from furan C₄H₄O.

Aldehyde of the Rubber Composition

In accordance with the invention, another essential constituent of theresin and of the composition is one or more aldehyde(s). Thus, inaccordance with the invention, the composition comprises one or morealdehyde(s).

Advantageously, the aldehyde is an aromatic aldehyde.

Such an aldehyde is very advantageous. Specifically, the Applicants havediscovered, during their research, that the aromatic aldehyde makes itpossible to avoid the production of formaldehyde, unlike conventionalmethylene donors. Specifically, the combination of phenolic resinconventionally used as methylene acceptor with HMT or H3M as methylenedonor in the prior art produces formaldehyde during the vulcanization ofthe rubber composition. However, it is desirable to reduce, or eveneliminate in the long run, formaldehyde from rubber compositions due tothe environmental impact of these compounds and the recent developmentsin regulations, especially European regulations, relating to this typeof compound.

An aromatic aldehyde is a compound containing at least one aromaticring, this aromatic ring bearing at least one (one or more) aldehydefunction.

Preferably, the aromatic aldehyde is selected from the group consistingof 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and analdehyde of formula (A):

in which:X comprises N, S or O,R represents —H or —CHO,and the mixtures of these compounds.

The aldehyde is preferentially of general formula (A′):

Even more preferentially, R represents —CHO.

According to a preferential embodiment, X represents O.

In a variant of the aldehyde of general formula (A), X represents O andR represents —H. The aldehyde used is then of formula (Ba):

In a variant of the aldehyde of general formula (A′), X represents O andR represents —H. The aldehyde used is then furfuraldehyde and is offormula (B′a):

In another variant of the aldehyde of general formula (A), X representsO and R represents —CHO. The aldehyde used is then of formula (Bb):

In another variant of the aldehyde of general formula (A′), X representsO and R represents —CHO. The aldehyde used is then2,5-furandicarboxaldehyde and is of formula (B′b):

In another embodiment, X comprises N.

In a variant of the aldehyde of general formula (A), X represents NH.The aldehyde used is of formula (Ca):

In a variant of the aldehyde of general formula (A′), X represents NH.The aldehyde used is of formula (C′a):

R preferably represents —CHO in the variant of the aldehyde of formula(C′a) and the aldehyde obtained is then 2,5-1H-pyrroledicarboxaldehyde.

In another variant of the aldehyde of general formula (A), X representsNR1′ with R1′ representing a radical selected from the group consistingof alkyl, aryl, arylalkyl, alkylaryl and cycloalkyl radicals. Thealdehyde used is of formula (Cb):

In another embodiment, X comprises S.

In a variant of the aldehyde of general formula (A), X represents S. Thealdehyde used is of formula (Da):

In a variant of the aldehyde of general formula (A′), X represents S.The aldehyde used is of formula (D′a):

R preferably represents —CHO in the variant of the aldehyde of formula(IV′a) and is then 2,5-thiophenedicarboxaldehyde.

In another variant of the aldehyde of general formula (A), X representsSR2′ with R2′ representing a radical selected from the group consistingof alkyl, aryl, arylalkyl, alkylaryl and cycloalkyl radicals. Thealdehyde used is of formula (Db):

In yet another variant of the aldehyde of general formula (A), Xrepresents R3′-S—R2′ with R2′ and R3′ representing, each independentlyof one another, a radical selected from the group consisting of alkyl,aryl, arylalkyl, alkylaryl and cycloalkyl radicals. The aldehyde used isof formula (Dc):

In yet another variant of the aldehyde of general formula (A), Xrepresents S═O. The aldehyde used is of formula (Dd):

In yet another variant of the aldehyde of general formula (A), Xrepresents O═S═O. The aldehyde used is of formula (De):

Among the different embodiments described above, preference will begiven to the embodiments and variants in which X represents NH, S or O.In these embodiments and variants, it will be possible, in accordancewith the invention, to have R representing —H or —CHO and preferably Rrepresenting —CHO. In these embodiments and variants, R willpreferentially be in the 5 position and the —CHO group willpreferentially be in the 2 position on the aromatic ring (generalformula (A′)).

Thus, more preferentially, the aromatic aldehyde is selected from thegroup consisting of 1,4-benzenedicarboxaldehyde, furfuraldehyde,2,5-furandicarboxaldehyde and the mixtures of these compounds.

The composition is preferably devoid of formaldehyde.

When the phenol-aldehyde resin is based on several aldehydes, at leastone of which is an aromatic aldehyde as described above, each aldehydeother than each aromatic aldehyde as described above is preferentiallydifferent from formaldehyde. The composition is then also preferentiallydevoid of formaldehyde.

In other words and preferably, the or each aldehyde of thephenol-aldehyde resin is different from formaldehyde.

“Devoid of formaldehyde” is intended to mean that the content by weightof formaldehyde, by total weight of the aldehyde or aldehydes, isstrictly less than 1%.

In some embodiments, the composition can comprise formaldehyde.Preferably, the composition then comprises a content by weight offormaldehyde, by total weight of the aldehyde or aldehydes, of less thanor equal to 10%, preferably to 5% and more preferentially to 2%.

Rubber Compositions According to the Invention

Depending on the use of the composition, an amount of aldehyde rangingfrom 0.1 to 25 phr will be used. Likewise, an amount of aromaticpolyphenol derivative ranging from 0.1 to 25 phr will be used.

In certain embodiments, the [aldehyde]:[aromatic polyphenol derivative]molar ratio advantageously varies from 3:1 to 1:1, advantageously from3:1 to 1.5:1.

Depending on the use that is made of the composition, the rubbercomposition has, in the cured state, a secant modulus at 10% elongation,MA10, measured according to standard ASTM D 412, 1998 (test specimen C)of greater than or equal to 10 MPa, preferably greater than or equal to20 MPa, preferentially greater than or equal to 30 MPa, morepreferentially greater than or equal to 40 MPa and even morepreferentially greater than or equal to 60 MPa.

The rubber composition preferably comprises a diene elastomer.

An elastomer or rubber (the two terms being synonymous) of the “diene”type is intended to mean, generally, an elastomer resulting at least inpart (i.e., a homopolymer or a copolymer) from diene monomers (monomersbearing two conjugated or unconjugated carbon-carbon double bonds).

Particularly preferentially, the diene elastomer of the rubbercomposition is selected from the group consisting of polybutadienes(BRs), synthetic polyisoprenes (IRs), natural rubber (NR), butadienecopolymers, isoprene copolymers and the mixtures of these elastomers.Such copolymers are more preferentially selected from the groupconsisting of butadiene/styrene copolymers (SBRs), isoprene/butadienecopolymers (BIRs), isoprene/styrene copolymers (SIRs),isoprene/butadiene/styrene copolymers (SBIRs) and the mixtures of suchcopolymers.

The rubber compositions may contain just one diene elastomer or amixture of several diene elastomers, it being possible for the dieneelastomer or elastomers to be used in combination with any type ofsynthetic elastomer other than a diene elastomer, or even with polymersother than elastomers, for example thermoplastic polymers.

The rubber composition preferably comprises a reinforcing filler.

When a reinforcing filler is used, use may be made of any type ofreinforcing filler known for its abilities to reinforce a rubbercomposition which can be used for the manufacture of tyres, for examplean organic filler, such as carbon black, a reinforcing inorganic filler,such as silica, or else a blend of these two types of filler, especiallya blend of carbon black and silica.

All the carbon blacks conventionally used in tyres (“tyre-grade” blacks)are suitable as carbon blacks. Mention will more particularly be made,for example, of the reinforcing carbon blacks of the 100, 200 or 300series (ASTM grades).

In the case of the use of carbon blacks with an isoprene elastomer, thecarbon blacks might, for example, be already incorporated in theisoprene elastomer in the form of a masterbatch (see, for example,applications WO 97/36724 or WO 99/16600).

Mention may be made, as examples of organic fillers other than carbonblacks, of functionalized polyvinylaromatic organic fillers, such asdescribed in applications WO-A-2006/069792 and WO-A-2006/069793.

“Reinforcing inorganic filler” should be understood, in the presentapplication, by definition, as meaning any inorganic or mineral filler,regardless of its colour and its origin (natural or synthetic), alsoreferred to as “white filler”, “clear filler” or even “non-blackfiller”, in contrast to carbon black, capable of reinforcing by itselfalone, without means other than an intermediate coupling agent, a rubbercomposition intended for the manufacture of tyres, in other wordscapable of replacing, in its reinforcing role, a conventional tyre-gradecarbon black. Such a filler is generally characterized, in a known way,by the presence of hydroxyl (—OH) groups at its surface.

The physical state in which the reinforcing inorganic filler is providedis not important, whether it is in the form of a powder, of micropearls,of granules, of beads or any other appropriate densified form. Ofcourse, reinforcing inorganic filler is also intended to mean mixturesof different reinforcing inorganic fillers, in particular of highlydispersible siliceous and/or aluminous fillers as described below.

Mineral fillers of the siliceous type, in particular silica (SiO₂), orof the aluminous type, in particular alumina (Al₂O₃), are especiallysuitable as reinforcing inorganic fillers. The silica used may be anyreinforcing silica known to those skilled in the art, especially anyprecipitated or fumed silica having a BET surface area and a CTABspecific surface area both of less than 450 m²/g, preferably from 30 to400 m²/g. Mention will be made, as highly dispersible precipitatedsilicas (“HDSs”), for example, of the Ultrasil 7000 and Ultrasil 7005silicas from Evonik, the Zeosil 1165MP, 1135MP and 1115MP silicas fromRhodia, the Hi-Sil EZ150G silica from PPG, the Zeopol 8715, 8745 and8755 silicas from Huber or the silicas with a high specific surface areaas described in application WO 03/16837.

Finally, those skilled in the art will understand that, as fillerequivalent to the reinforcing inorganic filler described in the presentsection, use might be made of a reinforcing filler of another,especially organic, nature, provided that this reinforcing filler iscovered with an inorganic layer, such as silica, or else comprisesfunctional sites, especially hydroxyl sites, at its surface whichrequire the use of a coupling agent in order to establish the bondbetween the filler and the elastomer.

The content of total reinforcing filler (carbon black and/or reinforcinginorganic filler, such as silica) is preferably within a range extendingfrom 5 to 120 phr, more preferentially from 5 to 100 phr and even morepreferentially from 5 to 90 phr.

The carbon black can advantageously constitute the sole reinforcingfiller or the predominant reinforcing filler. Of course, it is possibleto use just one carbon black or a blend of several carbon blacks ofdifferent ASTM grades. The carbon black can also be used as a blend withother reinforcing fillers and in particular reinforcing inorganicfillers as described above, in particular silica.

When an inorganic filler (for example silica) is used in the rubbercomposition, alone or as a blend with carbon black, its content iswithin a range from 0 to 70 phr, preferentially from 0 to 50 phr, inparticular also from 5 to 70 phr, and even more preferentially thisproportion varies from 5 to 50 phr, particularly from 5 to 40 phr.

The rubber composition preferably comprises various additives.

The rubber compositions may also comprise all or some of the standardadditives customarily used in the elastomer compositions intended forthe manufacture of tyres, such as for example plasticizers or extendingoils, whether the latter are aromatic or non-aromatic in nature,pigments, protective agents, such as antiozone waxes, chemicalantiozonants, antioxidants, antifatigue agents or else adhesionpromoters.

The rubber composition preferably comprises a crosslinking system, morepreferentially a vulcanization system.

The vulcanization system comprises a sulfur-donating agent, for examplesulfur.

The vulcanization system preferably comprises vulcanization activators,such as zinc oxide and stearic acid.

The vulcanization system preferably comprises a vulcanizationaccelerator and/or a vulcanization retarder.

The sulfur or sulfur-donating agent is used at a preferential contentwithin a range from 0.5 to 10 phr, more preferentially within a rangefrom 0.5 to 8.0 phr. The combined vulcanization accelerators, retardersand activators are used at a preferential content within a range from0.5 to 15 phr. The vulcanization activator or activators is or are usedat a preferred content within a range from 0.5 to 12 phr.

The crosslinking system proper is preferentially based on sulfur and ona primary vulcanization accelerator, in particular on an accelerator ofthe sulfenamide type. Additional to this vulcanization system arevarious known secondary vulcanization accelerators or vulcanizationactivators, such as zinc oxide, stearic acid, guanidine derivatives (inparticular diphenylguanidine), etc.

Use may be made, as (primary or secondary) accelerator, of any compoundcapable of acting as accelerator of the vulcanization of dieneelastomers in the presence of sulfur, especially accelerators of thethiazole type and their derivatives and accelerators of the thiuram andzinc dithiocarbamate types. These accelerators are more preferentiallyselected from the group consisting of 2-mercaptobenzothiazole disulfide(abbreviated to “MBTS”), N-cyclohexyl-2-benzothiazolesulfenamide(abbreviated to “CBS”), N,N-dicyclohexyl-2-benzothiazolesulfenamide(abbreviated to “DCBS”), N-(tert-butyl)-2-benzothiazolesulfenamide(abbreviated to “TBBS”), N-(tert-butyl)-2-benzothiazolesulfenimide(abbreviated to “TBSI”), zinc dibenzyldithiocarbamate (abbreviated to“ZBEC”) and the mixtures of these compounds. Use is preferably made of aprimary accelerator of the sulfenamide type.

In one embodiment, the rubber composition is in the cured state, i.e.vulcanized. In other embodiments, the composition is in the uncuredstate, i.e. unvulcanized, the crosslinked phenol-aldehyde resin havingbeen added subsequently to the unvulcanized composition.

In certain embodiments, the composition comprises a residue obtainedfrom the —Z radical of each —O—Z group. Prior to the crosslinking of theresin, and as assumed by the inventors behind the invention, afterforming each hydroxyl function, each Z radical of each —O—Z group maymake it possible to obtain a residue generated in situ. Certain residuesremain permanently in the composition and, where appropriate, may beused for some of the properties thereof.

In other embodiments, the residue generated only remains temporarily inthe composition either because it spontaneously leaves therefrom underthe conditions for manufacturing the composition, for example in theform of gas, especially in the case where the residue is volatile, orbecause an optional step of extracting this residue is carried out inthe method for manufacturing the composition.

In one embodiment, the phenol-aldehyde resin not yet having crosslinked,the rubber composition comprises:

-   -   at least one derivative of an aromatic polyphenol comprising at        least one aromatic ring bearing at least two —O—Z groups in the        meta position relative to one another, the two positions ortho        to at least one of the —O—Z groups being unsubstituted, Z being        other than hydrogen, and    -   at least one aldehyde.

Preferably, in this embodiment, the composition is in the uncured state,i.e. unvulcanized.

The rubber composition may preferably be used in the tyre in the form ofa layer. Layer is intended to mean any three-dimensional element havingany shape and any thickness, especially in the form of a sheet or strip,or other element having any cross section, for example rectangular ortriangular.

Of course, all the features relating to the derivative of the aromaticpolyphenol and to the aldehyde of the composition comprising the resinalso apply to the composition comprising the derivative of the aromaticpolyphenol and the aldehyde which are not crosslinked in the resinstate.

Rubber Composite According to the Invention

The rubber composite is reinforced with at least one reinforcing elementembedded in the rubber composition according to the invention.

This rubber composite can be prepared according to a process comprisingat least the following steps:

-   -   during a first step, combining at least one reinforcing element        with a rubber composition (or elastomer; the two terms are        synonymous) to form a rubber composite reinforced with the        reinforcing element;    -   then, during a second step, crosslinking by curing, for example        by vulcanizing, preferably under pressure, the composite formed        in this way.

Among reinforcing elements, mention may be made of textile, metallic, ortextile-metal hybrid reinforcing elements.

“Textile” is intended to mean, in a manner well known to those skilledin the art, any material made of a substance other than a metallicsubstance, whether natural or synthetic, which is capable of beingtransformed into thread or fibre by any appropriate transformationprocess. Mention may be made, for example, without the examples belowbeing limiting, of a polymer spinning process, such as, for example,melt spinning, solution spinning or gel spinning.

This textile material may consist of a thread or fibre, or also of afabric produced from threads or fibres, for example a woven fabric withwarp threads and weft threads, or else a twill fabric with crossthreads.

This textile material of the invention is preferably selected from thegroup consisting of monofilaments (or individual threads), multifilamentfibres, assemblies of such threads or fibres, and mixtures of suchmaterials. It is more particularly a monofilament, a multifilament fibreor a folded yarn.

The term thread or fibre is generally intended to mean any elongateelement of great length relative to its cross section, regardless of theshape, for example circular, oblong, rectangular, square, or even flat,of this cross section, it being possible for this thread to be straightor not straight, for example twisted or wavy. The largest dimension ofits cross section is preferentially less than 5 mm, more preferentiallyless than 3 mm.

This thread or fibre may take any known form. For example, it may be anindividual monofilament of large diameter (for example and preferablyequal to or greater than 50 μm), a multifilament fibre (consisting of aplurality of elementary filaments of small diameter, typically less than30 μm), a textile folded yarn or cord formed from several textile fibresor monofilaments twisted or cabled together, or else an assembly, groupor row of threads or fibres, such as, for example, a band or stripcomprising several of these monofilaments, fibres, folded yarns or cordsgrouped together, for example aligned along a main direction, whetherstraight or not.

The textile materials may be made of organic, polymeric or inorganicsubstances.

Mention will be made, as examples of inorganic substances, of glass orcarbon.

The invention is preferentially implemented with materials made ofpolymeric substance, of both the thermoplastic and non-thermoplastictype.

Mention will be made, as examples of polymeric substances of thenon-thermoplastic type, for example, of aramid (aromatic polyamide) andcellulose, both natural and artificial, such as cotton, rayon, flax orhemp.

Mention will preferentially be made, as examples of polymeric substancesof the thermoplastic type, of aliphatic polyamides and of polyesters.Mention may especially be made, among the aliphatic polyamides, of thepolyamides 4-6, 6, 6-6, 11 or 12. Mention may be made, among polyesters,for example, of PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), PBT (polybutylene terephthalate), PBN (polybutylenenaphthalate), PPT (polypropylene terephthalate), and PPN (polypropylenenaphthalate).

By definition, metallic is intended to mean one or more threadlikeelements made up predominantly (that is to say more than 50% of itsweight) or entirely (100% of its weight) of a metallic material. Themetallic material is preferably steel, more preferentially perlitic (orferritic-perlitic) carbon steel advantageously comprising between 0.4%and 1.2% by weight of carbon.

The metallic reinforcing element may be a monofilament, a cordcomprising several metallic monofilaments or a multistrand ropecomprising several cords, then referred to as strands.

In the preferred case in which the reinforcing element comprises severalmetallic monofilaments or several strands, the metallic monofilaments orthe strands are assembled by twisting or braiding. It is recalled thatthere are two possible techniques for assembly:

-   -   either by twisting: the metallic monofilaments or the strands        undergo both a collective twist and an individual twist about        their own axis, thereby generating an untwisting torque on each        of the monofilaments or strands;    -   or by braiding: the metallic monofilaments or the strands only        undergo a collective twist and do not undergo an individual        twist about their own axis.

The reinforcing element optionally comprises several monofilaments andis of the rubberized in situ type, that is to say that the reinforcingelement is rubberized from the inside, during the actual manufacturethereof, by a filling rubber. Such metallic threadlike elements areknown to those skilled in the art. The composition of the filling rubbermay be identical, or not identical, to the rubber composition in whichthe reinforcing element is embedded.

Tvre According to the Invention

Such tyres are, for example, those intended to be fitted onto motorvehicles of the passenger type, SUVs (“Sport Utility Vehicles”),two-wheel vehicles (especially bicycles and motorcycles), aircraft, orindustrial vehicles chosen from vans, “heavy-duty” vehicles—that is tosay underground trains, buses, heavy road transport vehicles (lorries,tractors, trailers), off-road vehicles, such as agricultural or civilengineering machines—and other transport or handling vehicles.

By way of example, appended FIG. 1 represents highly schematically(without being true to a specific scale) a radial section of a tyre inaccordance with the invention for a vehicle of the heavy-duty type.

This tyre 1 has a crown 2 reinforced by a crown reinforcement or belt 6,two sidewalls 3 and two beads 4, each of these beads 4 being reinforcedwith a bead wire 5. The crown 2 is surmounted by a tread, notrepresented in this diagrammatic figure. A carcass reinforcement 7 iswound around the two bead wires 5 in each bead 4, the turn-up 8 of thisreinforcement 7 being, for example, positioned towards the outside ofthe tyre 1, which is here represented fitted onto its wheel rim 9. Thecarcass reinforcement 7 is, in a way known per se, composed of at leastone ply reinforced by “radial” cords, for example made of metal, that isto say that these cords are positioned virtually parallel to one anotherand extend from one bead to the other so as to form an angle of between80° and 90° with the median circumferential plane (plane perpendicularto the axis of rotation of the tyre which is located halfway between thetwo beads 4 and passes through the middle of the crown reinforcement 6).

This tyre 1 of the invention has, for example, the characteristic thatat least a crown reinforcement 6 and/or its carcass reinforcement 7comprises a rubber composition or a composite according to theinvention. Of course, the invention relates to the objects describedpreviously, namely the rubber composite and the tyre, both in theuncured state (before curing or vulcanization) and in the cured state(after curing).

Method for Manufacturing the Composition According to the Invention

The manufacturing method described above and below makes it possible tomanufacture the composition according to the invention.

The rubber composition may be manufactured in suitable mixers, using twosuccessive preparation phases well known to those skilled in the art:

-   -   a first phase of thermomechanical working or kneading        (“non-productive” phase) at high temperature, up to a maximum        temperature of between 110° C. and 190° C., preferably between        130° C. and 180° C.,    -   followed by a second phase of mechanical working (“productive”        phase) down to a lower temperature, typically of less than 110°        C., for example between 40° C. and 100° C., during which        finishing phase the crosslinking system is incorporated.

In a first embodiment, the method comprises the following steps:

-   -   incorporating, in an elastomer, during a first step, a        reinforcing filler, everything being kneaded thermomechanically        until a maximum temperature of between 110° C. and 190° C. is        reached;    -   cooling the combined mixture to a temperature below 110° C.;    -   then incorporating, during a second step, a crosslinking system,        the derivative of the aromatic polyphenol and the aldehyde;    -   kneading everything at a temperature below 110° C.

By way of example, the non-productive phase is carried out in a singlethermomechanical step during which firstly all the necessary baseconstituents (diene elastomer, reinforcing filler etc.) are introducedinto an appropriate mixer, such as a standard internal mixer, thensecondly, for example after kneading for one to two minutes, the otheradditives, optional additional agents for covering the filler oroptional additional processing aids, with the exception of thecrosslinking system, the derivative of the aromatic polyphenol and thealdehyde, are introduced. The total kneading time, in thisnon-productive phase, is preferably between 1 and 15 min.

After cooling the mixture thus obtained, the crosslinking system, thealdehyde and the derivative of the aromatic polyphenol are thenincorporated in an external mixer, such as an open mill, maintained at alow temperature (for example between 40° C. and 100° C.). The combinedmixture is then mixed (productive phase) for a few minutes, for examplebetween 2 and 15 min.

The composition thus obtained in the uncured state can subsequently beshaped, for example calendered, for example in the form of a sheet or ofa slab, especially for laboratory characterization, or else extruded,for example in order to form a rubber profiled element used in themanufacture of a tyre.

Then, after an optional step of assembling together several compositionsformed as plies or strips in the form of a composite or an uncured tyreblank, a step of vulcanizing the composition, the composite or the blankis carried out during which the phenol-aldehyde resin based on thearomatic polyphenol derivative and on the aldehyde is crosslinked. Thevulcanization step is carried out at a temperature greater than or equalto 120° C., preferably greater than or equal to 140° C. The compositionis obtained in the cured state.

In a second embodiment, the method comprises the following steps:

-   -   incorporating, in an elastomer, during a first step, a        reinforcing filler, the derivative of the aromatic polyphenol        and the aldehyde, everything being kneaded thermomechanically        until a maximum temperature of between 110° C. and 190° C. is        reached;    -   cooling the combined mixture to a temperature below 110° C.;    -   subsequently incorporating, during a second step, a crosslinking        system;    -   kneading everything at a temperature below 110° C.

The invention and its advantages will be easily understood in the lightof the exemplary embodiments which follow.

Exemplary Embodiments of the Invention and Comparative Tests

These tests demonstrate that:

-   -   the stiffness of the rubber composition is greatly increased        relative to a rubber composition devoid of reinforcing resin;    -   the stiffness of the rubber composition according to the        invention may be improved compared to a rubber composition using        a conventional reinforcing resin based on a methylene acceptor        with HMT or H3M as methylene donor;    -   the stiffness retention of the rubber composition according to        the invention at high temperatures, in particular for        temperatures ranging up to 150° C., is equivalent to, or even        greater than in most embodiments, that of the rubber        compositions devoid of reinforcing resin and equivalent to, or        even greater than in certain embodiments, that of the        conventional rubber compositions that comprise HMT or H3M        methylene donors;    -   there is a delay phase during the crosslinking of the        phenol-aldehyde resin of the composition according to the        invention making it possible to avoid the premature crosslinking        of the resin relative to a phenol-aldehyde resin crosslinked        directly using the aromatic polyphenol and the aldehyde;    -   the phenol-aldehyde resin of the composition preferentially        using an aromatic aldehyde is devoid of formaldehyde and does        not generate any formaldehyde during its formation.

For this purpose, several rubber compositions, denoted hereinafter T0,T1 and T2 and I1 to I7 were prepared as indicated above and aresummarized in the appended Table 1 below.

All the compositions T0 to T2 and I1 to I7 have the following sharedportion in their formulations (expressed in phr, parts by weight perhundred parts of elastomer): 100 phr of natural rubber, 75 phr of carbonblack N326, 1.5 phr ofN-(1,3-dimethylbutyl)-N-phenyl-para-phenylenediamine, 1.5 phr of stearicacid, 5 phr of ZnO, 1 phr of N-(tert-butyl)-2-benzothiazolesulfamide and2.5 phr insoluble sulfur 20H.

The composition T0 does not comprise any reinforcing resin added to thisshared portion.

In addition to the shared portion, the composition T1 comprises areinforcing resin based on hexamethylenetetramine (1.6 phr) and on apre-condensed phenolic resin (4 phr). The composition T1 represents aconventional composition of the prior art, having greater stiffness thanthat of the composition T0.

In addition to the shared portion, the composition T2 comprises aphenol-aldehyde resin based on phloroglucinol and on1,4-benzenedicarboxaldehyde. The composition T2 comprises 7 phr ofphloroglucinol and 14 phr of 1,4-benzenedicarboxaldehyde.

In addition to the shared portion, each composition I1 to I7 comprisesan aromatic polyphenol derivative and an aldehyde, preferably anaromatic aldehyde, which are indicated in Table 1 in 1 (aromaticpolyphenol derivative)/2 (aldehyde) molar proportions, and with, in eachcomposition I1 to I7, 14 phr of the aldehyde.

The compositions T0, T1 and T2 are not in accordance with the invention,unlike compositions I1 to I7 which are in accordance with the invention.

In the uncured state, each rubber composition I1 to I7 according to theinvention comprises:

-   -   at least one derivative of an aromatic polyphenol comprising at        least one aromatic ring bearing at least two —O—Z groups in the        meta position relative to one another, the two positions ortho        to at least one of the —O—Z groups being unsubstituted, Z being        other than hydrogen, and    -   at least one aldehyde, preferably an aromatic aldehyde.

In the cured state, each rubber composition I1 to I7 according to theinvention comprises a phenol-aldehyde resin based:

-   -   on at least one derivative of an aromatic polyphenol comprising        at least one aromatic ring bearing at least two —O—Z groups in        the meta position relative to one another, the two positions        ortho to at least one of the —O—Z groups being unsubstituted, Z        being other than hydrogen, and    -   on at least one aldehyde, preferably an aromatic aldehyde.

Aromatic Polyphenol Derivatives of Compositions I1 to I7

Each aromatic polyphenol derivative of the resin of each composition I1to I7 according to the invention is selected from the group consistingof derivatives of resorcinol, of phloroglucinol, of2,2′,4,4′-tetrahydroxydiphenyl sulfide, of2,2′,4,4′-tetrahydroxybenzophenone and the mixtures of these compounds.

Each aromatic polyphenol derivative of each composition I1 to I7according to the invention comprises a single aromatic ring, in thiscase a benzene ring, bearing three, and only three, —O—Z groups in themeta position relative to one another.

For the derivatives of the aromatic polyphenols of each compositionaccording to the invention I1 to I7, the remainder of the aromatic ringof the derivative of the aromatic polyphenol is unsubstituted. Inparticular, the two positions ortho to each —O—Z group areunsubstituted. In the case in point, these are derivatives ofphloroglucinol.

Each aromatic polyphenol derivative of each composition I1 to I7according to the invention has an —O—Z group selected from the groupconsisting of the —O—Si(R₁R₂R₃), —O—C((═O)(R₄)) and —O—C((═O)(N(R₅R₆)))groups in which each R₁, R₂, R₃ and R₄ group represents, independentlyof one another, a hydrocarbon-based radical or a substitutedhydrocarbon-based radical and in which each R₅ and R₆ group represents,independently of one another, hydrogen, a hydrocarbon-based radical or asubstituted hydrocarbon-based radical.

Derivatives of the Aromatic Polyphenols of Compositions I1 to I3

Each derivative of the aromatic polyphenol of compositions I1 to I3 issuch that each —O—Z group represents an —O—Si(R₁R₂R₃) group with R₁, R₂,R₃ representing, independently of one another, a radical selected fromthe group consisting of alkyl, aryl, arylalkyl, alkylaryl, cycloalkyland alkenyl radicals. Preferably, each R₁, R₂, R₃ group represents,independently of one another, a radical selected from the groupconsisting of methyl, ethyl, propyl, phenyl, allyl and vinyl radicalsand more preferentially still a radical selected from the groupconsisting of methyl, ethyl, propyl, butyl, allyl and vinyl radicals.

The derivative of the aromatic polyphenol of composition I1 is such thatR₁═R₂═R₃═CH₃ and has the following formula (5):

The derivative (5) is prepared from phloroglucinol (CAS 108-73-6) andfrom trimethylsilyl chloride (CAS 75-77-4) in the presence of an organicbase. Thus, for example, 40 g of phloroglucinol are dissolved in 800 mlof chloroform. Next, 109 g of triethylamine are then added. Next, 107 gof trimethylsilyl chloride CISi(CH₃)₃ are added dropwise to the reactionmedium at ambient temperature. Everything is left stirring at ambienttemperature for 3 hours. Next, the reaction mixture is acidified with a37% aqueous solution of hydrochloric acid. Next, it is washed twice withwater. The final product is finally recovered after drying overanhydrous sodium sulfate, filtration and evaporation of the solvent. 150g of the derivative (5) are obtained in the form of a brown liquid. The¹H NMR spectrum of the derivative (5) is represented in FIG. 2A NMR(CDCl₃, 300 MHz): 6.03 (3H, s), 0.27 (27H, s)).

The derivative of the aromatic polyphenol of composition I2 is such thatR₁═R₂═CH₃, R₃═CH═CH₂ and has the following formula (6):

The derivative (6) is prepared in a similar manner to the derivative (5)from phloroglucinol (CAS 108-73-6) and from dimethylvinylsilyl chloride(CAS 1719-58-0). The ¹H NMR spectrum of the derivative (6) isrepresented in FIG. 3A (¹H NMR (CDCl₃, 300 MHz): 6.15-5.60 (9H, m), 5.89(3H, s), 0.15 (18H, s)).

The derivative of the aromatic polyphenol of composition I3 is such thatR₁═CH₃, R₂═R₃═C₆H₆ and has the following formula (7):

The derivative (7) is prepared in a similar manner to the derivative (5)from phloroglucinol (CAS 108-73-6) and from methyldiphenylsilyl chloride(CAS 144-79-6). The ¹H NMR spectrum of the derivative (7) is representedin FIG. 4A NMR (CDCl₃, 300 MHz): 7.70-7.30 (30H, m), 6.03 (3H, s), 0.59(9H, s)).

Derivatives of the Aromatic Polyphenols of Compositions I4 to I6

Each derivative of the aromatic polyphenol of compositions I4 to I6 issuch that each —O—Z group represents an —O—C((═O)(R₄)) group with R₄representing a radical selected from the group consisting of alkyl,aryl, arylalkyl, alkylaryl, cycloalkyl and alkenyl radicals. Preferably,R₄ represents a radical selected from the group consisting of methyl,ethyl, propyl, butyl, allyl and vinyl radicals.

The derivative of the aromatic polyphenol of composition I4 is such thatR₄═CH₃ and has the following formula (8) (CAS 2999-40-8):

The derivative (8) is prepared from phloroglucinol (CAS 108-73-6) andfrom acetyl chloride (CAS 75-36-5) in the presence of an organic base.Thus, for example, 18 g of phloroglucinol and 64 g of triethylamine aredissolved in 450 ml of tetrahydrofuran. Next, 45 g of acetyl chlorideare added dropwise to the reaction medium at ambient temperature.Everything is left stirring at ambient temperature for 3 hours. Next,the reaction medium is filtered and the tetrahydrofuran is evaporated.The product is then dissolved in the chloroform and an acid extractionis carried out followed by an extraction with clean water. The finalproduct is finally recovered after drying over anhydrous sodium sulfate,filtration and evaporation of the solvent. 36 g of the derivative areobtained in the form of a yellow powder. The ¹H NMR spectrum of thederivative (8) is represented in FIG. 5A (¹H NMR (CDCl₃, 300 MHz): 6.85(3H, s), 2.28 (9H, s)).

The derivative of the aromatic polyphenol of composition I5 is such thatR₄═C₁₇H₃₅ and has the following formula (9):

The derivative (9) is prepared in a similar manner to the derivative (8)from phloroglucinol (CAS 108-73-6) and from stearoyl chloride (CAS112-76-5). The ¹H NMR spectrum of the derivative (9) is represented inFIG. 6A (¹H NMR (CDCl₃, 300 MHz): 6.84 (3H, s), 2.47 (6H, t), 1.87-1.16(90H, m) 0.90 (9H, t)).

The derivative of the aromatic polyphenol of composition I6 is such thatR₄═C₁₁H₂₃ and has the following formula (10):

The derivative (10) is prepared in a similar manner to the derivative(8) from phloroglucinol (CAS 108-73-6) and from lauroyl chloride (CAS112-16-3). The ¹H NMR spectrum of the derivative (10) is represented inFIG. 7A (¹H NMR (CDCl₃, 300 MHz): 6.83 (3H, s), 2.54 (6H, t), 1.84-1.62(6H, m), 1.28 (48H, m), 0.90 (9H, t)).

Derivative of the Aromatic Polyphenol of Composition I7

The derivative of the aromatic polyphenol of composition I7 is such thateach —O—Z group represents an —O—C((═O)(N(R₅R₆))) group with R₅, R₆representing, independently of one another, hydrogen or a radicalselected from the group consisting of alkyl, aryl, arylalkyl, alkylaryl,cycloalkyl, alkenyl and allyl radicals. Preferentially, each R₅, R₆group represents, independently of one another, hydrogen or a radicalselected from the group consisting of methyl, ethyl, propyl, butyl,allyl or vinyl radicals.

The derivative of the aromatic polyphenol of composition I7 is such thatR₅═H and R₆═C₆H₆ and has the following formula (11):

The derivative (11) is prepared from phloroglucinol (CAS 108-73-6) andfrom phenyl isocyanate (CAS 103-71-9). 5 g (0.040 mol) of phloroglucinoland 30 ml of dioxane are introduced into a two-necked round-bottomedflask. The mixture is placed under stirring at ambient temperature then14.18 g (0.119 mol) of phenyl isocyanate are added via a droppingfunnel. At the end of the addition, 200 mg of dibutyltin dilaurate areadded. The temperature is raised to 80° C. for a period of 8 h. At theend of the reaction, the dioxane is evaporated under reduced pressurethen the final product is dried in an oven under vacuum. The finalproduct is a white powder obtained with a yield of 94%. The ¹H NMRspectrum of the derivative (11) is represented in FIG. 8A (¹H NMR(DMSO-d6, 300 MHz): 7.00-6.05 (15H, m), 6.24 (3H, s)).

Aldehyde of Compositions I1 to I7

Each aldehyde of each composition I1 to I7 according to the invention isa preferentially aromatic aldehyde and is selected from the groupconsisting of 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehydeand an aldehyde of formula (A):

in which:X comprises N, S or O,R represents —H or —CHO, and the mixtures of these compounds.

In this case, the aldehyde is selected from the group consisting of1,4-benzenedicarboxaldehyde, furfuraldehyde, 2,5-furandicarboxaldehydeand the mixtures of these compounds. Here, the aldehyde of eachcomposition I1 to I7 according to the invention is1,4-benzenedicarboxaldehyde.

Comparative Tests

In a first step, the reinforcing filler was incorporated into anelastomer, everything being kneaded thermomechanically until a maximumtemperature of between 110° C. and 190° C. was reached. Then thecombined mixture was cooled to a temperature below 110° C. Next, duringa second step, the crosslinking system, the phenol, the aromaticpolyphenol or the derivative of the aromatic polyphenol and the aldehydewere incorporated. At the end of this second step, the mixture washeated to 150° C. until the maximum rheometric torque was obtained inorder to vulcanize the composition and crosslink the phenol-aldehyderesin. Next, the stiffness at 23° C. of the composition wascharacterized during a tensile test.

Characterization of the Delay Phase and of the Stiffness at HighTemperature—Maximum Rheometric Torque

The measurements are carried out at 150° C. with an oscillating discrheometer, according to standard DIN 53529—Part 3 (June 1983). Thechange in the rheometric torque as a function of the time describes thechange in the stiffening of the composition following vulcanization andcrosslinking of the phenol-aldehyde resin. From the change in therheometric torque, the presence of a delay phase is determined when theincrease in the rheometric torque, over 10 minutes, of the compositiontested is lower than the increase in the rheometric torque, over 10minutes, of a control composition comprising the corresponding aromaticpolyphenol and the same aldehyde, here the composition T2. The presenceof such a delay phase is indicated in Table 1. Each curve thatrepresents the change in the rheometric torque respectively ofcompositions I1 to I7 and also those that represent the change in therheometric torque of compositions T0, T1 and T2 have been represented inFIGS. 2B to 8B.

The higher the maximum rheometric torque Cmax, the more the compositionhas a stiffness which can be maintained at high temperature.

Characterization of the Stiffness at 23° C.—Tensile Test

These tests make it possible to determine the elasticity stresses andthe properties at break. Unless indicated otherwise, they are carriedout in accordance with standard ASTM D 412, 1998 (test specimen C). The“nominal” secant moduli (or apparent stresses, in MPa) at 10% elongation(denoted “MA10”) are measured in second elongation (i.e., after anaccommodation cycle). All these tensile measurements are carried outunder normal temperature and relative humidity conditions, according tostandard ASTM D 1349, 1999, and are reported in Table 1.

Firstly, the results from Table 1 show that the use of an aromaticpolyphenol and of an aldehyde in the control composition T2 makes itpossible to obtain a stiffness at 23° C. that is much higher than thatof a composition devoid of reinforcing resin (T0) but also than that ofa composition comprising a reinforcing resin of the prior art (T1).However, the composition T2 has no delay phase so that thephenol-aldehyde resin of the composition T2 crosslinks prematurely.

In addition to its delay phase, each composition according to theinvention I1 to I7 has a stiffness at 23° C. that is equivalent to oreven greater than that of the composition T1. Furthermore, unlike T1,each composition I1 to I7 does not produce formaldehyde during thevulcanization thereof.

Each composition according to the invention I1 to I7 has a delay phaseand a stiffness which, although lower than that of the composition T2 incertain examples described, is sufficient to enable a reinforcement ofthe rubber composition. Moreover, this stiffness may be increased bymodifying other parameters such as the contents of aromatic polyphenolderivative and aldehyde used.

Each composition according to the invention I1 to I7 has an improvedstiffness retention at high temperatures (Cmax) compared to theretentions of composition T0. Furthermore, the compositions according tothe invention I1 to I4 have a stiffness retention at high temperatures(Cmax) which is at least equal (I2) or even significantly higher (I1, I3and I4) than that of the composition T1.

It will also be noted that the delay phase and the stiffness at 23° C.may be selected as a function of the application by varying the —O—Zgroup and in particular the R₁ to R₆ groups.

The invention is not limited to the embodiments described above.

In other embodiments not present in Table 1, aromatic polyphenolderivatives comprising several aromatic rings, for example benzenerings, could be envisaged, at least two of these rings each bearing atleast two —O—Z groups in the meta position relative to one another. Thetwo positions ortho to at least one of the —O—Z groups of each aromaticring are unsubstituted.

Use may be made of an aromatic polyphenol derivative as described aboveby using it to generate a delay phase during the crosslinking of aphenol-aldehyde resin based on the aromatic polyphenol derivative and onan aldehyde, independently of the use thereof for the manufacture of aphenol-aldehyde resin for reinforcing a rubber composition. Thecharacteristics of the aromatic polyphenol derivative and of thealdehyde described above also apply to this use for generating a delayphase during the crosslinking of the phenol-aldehyde resin.

Use may likewise be made, in certain embodiments, of an aromaticpolyphenol derivative as described above by using it in aphenol-aldehyde resin to maintain the stiffness of a rubber compositionwith the increase in the temperature, independently of the use thereoffor the manufacture of a phenol-aldehyde resin for reinforcing a rubbercomposition. The characteristics of the aromatic polyphenol derivativeand of the aldehyde described above also apply to this use in aphenol-aldehyde resin for maintaining the stiffness of the rubbercomposition with the increase in the temperature.

TABLE 1 Delay MA10 Cmax Composition Phenol Methylene donor phase (MPa)(dN · m) T0 / / /  7.4 16 T1 SRF resin (1) Hexamethylenetetramine (2) No16.5 43 Delay MA10 Cmax Composition Aromatic polyphenol Aldehyde phase(MPa) (dN · m) T2 Phloroglucinol (3) 1,4-Benzenedicarboxaldehyde (4) No33.5 46 Aromatic polyphenol derivative Delay MA10 Cmax CompositionZ═Si(R₁R₂R₃) Aldehyde phase (MPa) (dN · m) I1 R₁═R₂═R₃═CH₃ (5)1,4-Benzenedicarboxaldehyde (4) Yes 24.9 65 I2 R₁═R₂═CH₃, R₃═CH═CH₂ (6)1,4-Benzenedicarboxaldehyde (4) Yes 23.8 43 I3 R₁═CH₃, R₂═R₃═C₆H₅ (7)1,4-Benzenedicarboxaldehyde (4) Yes 16.6 50 Aromatic polyphenolderivative Delay MA10 Cmax Composition Z═(C(═O)(R₄)) Aldehyde phase(MPa) (dN · m) I4 R₄═CH₃ (8) 1,4-Benzenedicarboxaldehyde (4) Yes 29.9 64I5 R₄═C₁₇H₃₅ (9) 1,4-Benzenedicarboxaldehyde (4) Yes 14.9 17 I6R₄=C₁₁H₂₃ (10) 1,4-Benzenedicarboxaldehyde (4) Yes 14.4 21 Aromaticpolyphenol derivative Delay MA10 Cmax Composition Z═(C(═O)(NR₅R₆))Aldehyde phase (MPa) (dN · m) I7 R₅═H, R₆═C₆H₅ (11)1,4-Benzenedicarboxaldehyde (4) Yes 36.4 27 (1) Hexamethylenetetramine(from Sigma-Aldrich; purity of ≥99%); (2) Pre-condensed resin SRF 1524(from Schenectady; diluted to 75%); (3) Phloroglucinol (from Alfa Aesar;purity of 99%); (4) 1,4-Benzenedicarboxaldehyde (from ABCR; purity of98%).

1.-28. (canceled)
 29. A rubber composition comprising at least onephenol-aldehyde resin based: on at least one derivative of an aromaticpolyphenol comprising at least one aromatic ring bearing at least two—O—Z groups in the meta position relative to one another, the twopositions ortho to at least one of the —O—Z groups being unsubstituted,Z being other than hydrogen, and on at least one aldehyde.
 30. Therubber composition according to claim 29, wherein the aromatic ring ofthe at least one derivative of the aromatic polyphenol bears three —O—Zgroups in the meta position relative to one another.
 31. The rubbercomposition according to claim 29, wherein the two positions ortho toeach —O—Z group are unsubstituted.
 32. The rubber composition accordingto claim 29, wherein the remainder of the aromatic ring of the at leastone derivative of the aromatic polyphenol is unsubstituted.
 33. Therubber composition according to claim 29, wherein the at least onederivative of the aromatic polyphenol comprises several aromatic rings,at least two of these each bearing at least two —O—Z groups in the metaposition relative to one another, the two positions ortho to at leastone of the —O—Z groups of at least one aromatic ring beingunsubstituted.
 34. The rubber composition according to claim 29, whereinthe, or each, aromatic ring of the at least one derivative of thearomatic polyphenol is a benzene ring.
 35. The rubber compositionaccording to claim 29, wherein the at least one derivative of thearomatic polyphenol is selected from the group consisting of derivativesof resorcinol, phloroglucinol, 2,2′,4,4′-tetrahydroxydiphenyl sulfide,2,2′,4,4′-tetrahydroxybenzophenone and mixtures thereof.
 36. The rubbercomposition according to claim 29, wherein each —O—Z group is selectedfrom the group consisting of —O—Si(R₁R₂R₃), —O—C((═O)(R₄)) and—O—C((═O)(N(R₅R₆))) groups in which each R₁, R₂, R₃ and R₄ grouprepresents, independently of one another, a hydrocarbon-based radical ora substituted hydrocarbon-based radical and each R₅ and R₆ grouprepresents, independently of one another, hydrogen, a hydrocarbon-basedradical or a substituted hydrocarbon-based radical.
 37. The rubbercomposition according to claim 29, wherein each —O—Z group represents an—O—Si(R₁R₂R₃) group with R₁, R₂, R₃ representing, independently of oneanother, a radical selected from the group consisting of alkyl, aryl,arylalkyl, alkylaryl, cycloalkyl and alkenyl radicals.
 38. The rubbercomposition according to claim 29, wherein each —O—Z group represents an—O·C((═O)(R₄)) group with R₄ representing a radical selected from thegroup consisting of alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl andalkenyl radicals.
 39. The rubber composition according to claim 29,wherein each —O—Z group represents an —O—C((═O)(N(R₅R₆))) group with R₅,R₆ representing, independently of one another, a radical selected fromthe group consisting of alkyl, aryl, arylalkyl, alkylaryl, cycloalkyland alkenyl radicals and hydrogen.
 40. The rubber composition accordingto claim 29, wherein the aromatic polyphenol derivative is apre-condensed resin based: on at least one aromatic polyphenolcomprising at least one aromatic ring bearing at least two hydroxylfunctions in the meta position relative to one another, the twopositions ortho to at least one of the hydroxyl functions beingunsubstituted; and on at least one compound comprising at least onealdehyde function, wherein the hydroxyl functions of the pre-condensedresin which remained reactive at the end of the condensation of thepre-condensed resin are substituted by —O—Z groups.
 41. The rubbercomposition according to claim 29, wherein the compound comprising atleast one aldehyde is selected from the group consisting offormaldehyde, benzaldehyde, furfuraldehyde, 2,5-furandicarboxaldehyde,1,4-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldehyde,1,2-benzenedicarboxaldehyde and mixtures thereof.
 42. The rubbercomposition according to claim 29, wherein the at least one aldehyde isan aromatic aldehyde.
 43. The rubber composition according to claim 42,wherein the aromatic aldehyde is selected from the group consisting of1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and an aldehydeof formula

in which X comprises N, S or O; R represents —H or —CHO, and mixturesthereof.
 44. The rubber composition according to claim 42, wherein thearomatic aldehyde is selected from the group consisting of1,4-benzenedicarboxaldehyde, furfuraldehyde, 2,5-furandicarboxaldehydeand mixtures thereof.
 45. The rubber composition according to claim 29further comprising a diene elastomer selected from the group consistingof polybutadienes, synthetic polyisoprenes, natural rubber, butadienecopolymers, isoprene copolymers and mixtures thereof.
 46. The rubbercomposition according to claim 29, wherein the rubber composition is inthe cured state.
 47. The rubber composition according to claim 29further comprising a residue obtained from the Z radical of each —O—Zgroup.
 48. A rubber composition comprising: at least one derivative ofan aromatic polyphenol comprising at least one aromatic ring bearing atleast two —O—Z groups in the meta position relative to one another, thetwo positions ortho to at least one of the —O—Z groups beingunsubstituted, Z being other than hydrogen; and at least one aldehyde.49. The rubber composition according to claim 29, wherein the rubbercomposition is in the uncured state.
 50. A method for manufacturing arubber composition in the uncured state comprising the step of: mixingat least one derivative of an aromatic polyphenol comprising at leastone aromatic ring bearing at least two —O—Z groups in the meta positionrelative to one another, the two positions ortho to at least one of the—O—Z groups being unsubstituted, Z being other than hydrogen, and atleast one aldehyde.
 51. The method according to claim 50 furthercomprising the steps of: incorporating, in an elastomer, during a firststep, a reinforcing filler, and kneading thermomechanically until amixture with a maximum temperature of between 110° C. and 190° C. isreached; cooling the mixture to a temperature below 110° C.; thenincorporating, during a second step, a crosslinking system, thederivative of the aromatic polyphenol and the aldehyde; and kneading ata temperature below 110° C.
 52. A method for manufacturing a rubbercomposition in the cured state comprising the steps of: manufacturing arubber composition in the uncured state comprising mixing at least onederivative of an aromatic polyphenol comprising at least one aromaticring bearing at least two —O—Z groups in the meta position relative toone another, the two positions ortho to at least one of the —O—Z groupsbeing unsubstituted, Z being other than hydrogen, and at least onealdehyde; and then shaping the rubber composition in the uncured state;and then vulcanizing the rubber composition during which aphenol-aldehyde resin based on the aromatic polyphenol derivative and onthe aldehyde is crosslinked.
 53. A rubber composition obtained by amethod according to claim
 50. 54. A rubber composition obtained by amethod according to claim
 52. 55. A rubber composite reinforced with atleast one reinforcing element embedded in a rubber composition accordingto claim
 29. 56. A tire comprising a rubber composition according toclaim
 29. 57. A tire comprising a rubber composite according to claim55.